Key indicating switch

ABSTRACT

A key indicating switch includes a dielectric housing mounted on the casing of an ignition lock. Spaced electrical contacts are mounted in the housing and connected in a key reminder circuit. A spring contact has one end attached to the housing and the other end self-biased into engagement with the spaced contacts. The spring contact includes a first intermediate rib engaging the housing and a second rib engaged by an actuating lever pivotally mounted to the housing. A spring biased plunger in the core normally causes the actuating lever to pivot the spring contact about its first rib to move the contact out of engagement with the spaced contacts. When a key is inserted into the key slot, the plunger releases the lever and the spring contact is selfbiased into engagement with the spaced contacts. Thus, the switch is self-biased to the closed position at all times.

Krom et al.

[ Apr. 23, 1974 KEY INDICATING SWITCH Primary Examiner-Herman Hohauser Attorney, Agent, or Firm-Herbert Furman [75] Inventors: Lynn C. Krom; Richard P. Riefel,

both of Saginaw, MlCh. ABSTRACT [73] Assign: Mfmrs corpm'afion A key indicating switch includes a dielectric housing Dem), mounted on the casing of an ignition lock. Spaced [22] Filed; May 16, 7 electrical contacts are mounted in the housing and connected in a key reminder circuit. A spring contact [21] Appl- 360,631 has one end attached to the housing and the other end self-biased into engagement with the spaced contacts. [52 us. Cl. 200/44, 200/6166 The Spring eehtaet includes a first intermediate rib en? [51 int. CI. H01h 27/06 gaging the housing and avseeehd rib engaged y an 58 Field of Search 200/61, 66, 42 R, 44; mating lever pivetally mounted to the s- A 70/237 239 spring biased plunger in the core normally causes the actuating lever to pivot the spring contact about its 5 References Cited first rib to move the contact out of engagementwith UNITED STATES PATENTS the spaced contacts. When a key is inserted into the key slot, the plunger releases the lever and the spring if contact is self-biased into engagement with the spaced contacts. Thus, the switch is self-biased to the closed position at all times.

I 3 Claims, 6 Drawing Figures II [III KEY INDICATING SWITCH The invention relates to a lock cylinder having a key indicating switch assembly.

It is known to provide an ignition lock having a switch which is closed upon insertion of the key into the lock. Such a switch is typically connected to an electrical buzzer circuit to indicate the presence of the key in the lock and thereby remind the vehicle operator to remove the key from the lock when exiting the vehicle.

According to the present invention, an improved key indicating switch for an ignition lock is provided. The key indicating switch includes a dielectric housing mounted on the outer casing of the ignition lock assembly. Mounted in the housing are laterally spaced electrical contacts which are connected in the key reminder circuit. An elongated spring contact has one end attached to the housing and the other end selfbiased into contact with the laterally spaced electrical contacts. The elongated spring contact is bent intermediate its ends to provide a first rib which engages the housing and a second rib engaged by an actuating lever pivotally mounted to the housing. A plunger is captured in a recess of the core and engages the actuating lever. A compression spring biases the plunger to a position wherein the plunger extends into the key slot and also engages and pivots the actuating lever to pivot the elongated spring contact about its first rib and move the end of the contact out of engagement with the spaced electrical contacts. When a key. is inserted into the key slot, the plunger is lifted against the bias of the compression spring and the spring contact is self-biased to its normal unexercised state wherein it electrically connects the laterally spaced electrical contacts.

Thus, the spring contact is self-biased to a closed position and normally opened by a switch operating linkage, Thus, upon failure of any of the elements which operate the switch, the switch is self-biased to the closed position thereby operating the key reminder signal to signify the need for repair or replacement of the switch.

These and other features, objects and advantages of the invention will become apparent upon consideration of the specification and the appended drawings in which:

FIG. 1 is an elevation view of an ignition lock assembly according to the invention;

FIG. 2 is an end view taken in the direction of arrows 2-2 of FIG. 1;

FIG. 3 is an elevation view similar to FIG. I having parts broken away and in section;

FIG. 4 is a view similar to FIG. 3 showing the key inserted and the key reminder switch in closed position;

FIG. 5 is a sectional view taken in the direction of arrows 5-5 of FIG. 3; and

cluding a conventional arrangement of tumblers and a locking bar, acts between the core 16 in the casing 12 to prevent rotation of the core within the outer casing until a properly bitted key 20, FIG. 4, is inserted into a key slot 22, FIG. 2, of the core 16.

This invention provides a key indicating switch which is closed upon insertion of the key into the key slot 22. The switch includes an elongated housing 24 of dielectric material which is conventionally secured within a slot 25, FIG. 2, of casing 12 and extends for substantially the full length of the casing. Laterally spaced angular contacts 26 seat against the upper and side walls of a hollow recess 28 of the housing as best seen in FIG. 5. Each contact includes a connector portion 30 which extends through the housing to the left of the recess 28 and outwardly of the inner end of the housing as shown in FIG. 1. The connector portions of the contact are connected in a key reminder or other conventional circuit which is intended to be closed and actuate an alarm or signal when the key 20 is inserted in the key slot 22. I

An elongated spring contact 32 has a lateral flange 34 at its outer end 36 which engages the right-hand end of the housing 24 to locate the contact 32 within the recess 30. A plurality of barbs 38, FIG. 6, on portion 36 engage laterally spaced ribs 40 on the upper and side walls of the recess 28 to mount the outer end of the contact 32 on the housing. As shown in FIG. 4, when the spring contact 32 is in its closed position, the inner end 42 thereof seats against the contacts 26 to complete the electrical circuit across the connector portions 30 of these contacts. The spring contact 32 is bent intermediate its inner and outer ends 36 and 42, respectively, to provide a pair of ribs 44 and 46. The former engages the upper wall of the recess 28 and the latter engages a leg 48 of an actuating lever 50. The actuating lever is also of dielectric material and includes integral pivot shafts 52 which are snapped into respective keyhole slots 54 provided in the side walls of the recess 28. The bottom and end walls of the recess are open at the outer end thereof to provide space for free swinging movement of the lever 50. The other leg 56 of the actuating lever is of arcuate cross section andextends outwardly of the outer end of the recess 28 for engagement by an arcuate lateral tab or flange 58 of a plunger 60 as shown in FIG. 2.

The plunger 60 is caged in a recess'62 of the core 16. A compression spring 64 seats between an abutment 66 of the recess and a lanced tab or flange 68 of the plunger tonormally bias the plunger downwardly as viewed in FIG. 2. This in turn biases the lever 50 clockwise as viewed in FIG. 3. The engagement of leg 48 with rib 46 partially flattens this rib to in turn bias the inner end 42 of the contact 32 out of engagement with the contacts 26. Thus the switch provided by the contacts 26 is normally open.

The plunger 60, as best shown in FIG. 2, includes a projecting arm 70 which seats against a shoulder 72 of the recess 62 to normally locate the plunger in its position shown in FIG. 2 when there is no key within the slot 22. With reference to this figure, it will be noted that the arm 70 also partially overlies the key slot 22.

When the key 20 is inserted in the key slot 22 as shown in FIG. 4, the engagement of the upper edge of the key with the arm 70 of plunger 62 moves the plunger upwardly against the action of spring 64. This moves the tab 58 of the plunger out of engagement with the leg 56 of the actuating lever. The biasing action of the ribs 44 and 46 of contact 32 thereupon moves the contact to its closed position as shown in FIG. 4 to complete the circuit. The plunger 60, of course, rotates with the core 16 when the core is rotated by the key 20. However, when the ignition is turned off or, in other words, the core 16 returned to its position shown in FIG. 4, the switch contacts 26 will actuate the reminder circuit until the key 20 is withdrawn.

Thus it is seen that a key reminder switch is provided which is self-biased to a closed position and normally opened by a switch operating linkage. Upon failure of any of the elements of the switch operating linkage, the switch is self-biased to the closed position thereby operating the key reminder signal to signify the need for switch repair or replacement.

What is claimed is:

1. In a lock assembly having a casing, a core rotatable in the casing and having a key receiving slot, and locking means acting between the core and the casing to normally lock the core from rotation in the casing and to unlock the core to permit rotation when a properly bitted key is inserted into the key slot, a switch for indicating the presence of the key in the key slot of the core and comprising: a switch housing of dielectric material mounted on the'casing, laterally spaced first and second electrical contacts mounted on the switch housing, an elongated spring contact mounted on the housing, cooperating means on the spring contact and housing to self-bias the contact into engagement with the laterally spaced electrical contacts and provide an electrical connection therebetween, an actuating lever pivotally mounted to the housing and engageable with the spring contact to move the spring contact out of engagement with the laterally spaced contacts, a key actuated plunger mounted on the core, means biasing the plunger into operative engagement with the actuating lever to pivot the actuating lever and move the spring contact out of engagement with the spaced contact and means on the plunger engageable by a key inserted into the key slot to move the plungerout of operative engagement with the actuating lever.

2. In a lock assembly having a casing, a core rotatable in the casing and having a central key receiving slot, and locking means acting between the core and the casing to normally lock the core from rotationin the casing and to unlock the core to permit rotation when a properly bitted key is inserted into the key slot, a switch for indicating the presence of the key in the key slot of the core and comprising: a switch housing of dielectric material mounted on the casing, laterally spaced first and second electrical contacts mounted on the switch housing, an elongated bent spring contact mounted on the housing and being self-biased into contact with the laterally spaced electrical contacts to provide an electrical connection therebetween, actuating means including spring means and being effective to exercise the elongated bent spring Contact against its self-bias to bias the bent spring contact out of engagement with the laterally spaced contacts, the actuating means including spring means being overcome upon insertion of the key into the key slot to permit self-bias return of the bent spring contact to the unexerciscd condition wherein the laterally spaced electrical contacts are connected, the self-bias of the bent spring contact being effective upon failure of the actuating means including spring means to close the switch to thereby signal the failure.

3. In a lock assembly having a casing, a core rotatable in the casing and having a central key receiving slot, and locking means acting between the core and the casing to normally lock the core from rotation in the casing and to unlock the core to permit rotation when a properly bitted key is inserted into the key slot, a switch for indicating the presence of the key in the key slot of the core and comprising: a switch housing of dielectric material mounted on the casing, laterally spaced first and second electrical contacts mounted on the switch housing, an elongated spring contact having one end mounted on the housing and the other end contacting the laterally spaced electrical contacts, the spring contact being bent intermediate its ends to provide a first ridge engaging the housing and a second ridge, an actuating lever pivotally mounted to the housing and engageable with the second ridge of the bent spring contact, a plunger mounted in a recess of the core, spring means biasing the plunger to a position wherein the plunger extends into the key slot and also engages and pivots the actuating lever to pivot the spring contact about its first ridge and out of contact with the laterally spaced electrical contacts, the plunger being connected. 

1. In a lock assembly having a casing, a core rotatable in the casing and having a key receiving slot, and locking means acting between the core and the casing to normally lock the core from rotation in the casing and to unlock the core to permit rotation when a properly bitted key is inserted into the key slot, a switch for indicating the presence of the key in the key slot of the core and comprising: a switch housing of dielectric material mounted on the casing, laterally spaced first and second electrical contacts mounted on the switch housing, an elongated spring contact mounted on the housing, cooperating means on the spring contact and housing to self-bias the contact into engagement with the laterally spaced electrical contacts and provide an electrical connection therebetween, an actuating lever pivotally mounted to the housing and engageable with the spring contact to move the spring contact out of engagement with the laterally spaced contacts, a key actuated plunger mounted on the core, means biasing the plunger into operative engagement with the actuating lever to pivot the actuating lever and move the spring contact out of engagement with the spaced contact and means on the plunger engageable by a key inserted into the key slot to move the plunger out of operative engagement with the actuating lever.
 2. In a lock assembly having a casing, a core rotatable in the casing and having a central key receiving slot, and locking means acting between the core and the casing to normally lock the core from rotation in the casing and to unlock the core to permit rotation when a properly bitted key is inserted into the key slot, a switch for indicating the presence of the key in the key slot of the core and comprising: a switch housing of dielectric material mounted on the casing, laterally spaced first and second electrical contacts mounted on the switch housing, an elongated bent spring contact mounted on the housing and being self-biased into contact with the laterally spaced electrical contacts to provide an electrical connection therebetween, actuating means including spring means and being effective to exercise the elongated bent spring contact against its self-bias to bias the bent spring contact out of engagement with the laterally spaced contacts, the actuating means including spring means being overcome upon insertion of the key into the key slot to permit self-bias return of the bent spring contact to the unexercised condition wherein the laterally spaced electrical contacts are connected, the self-bias of the bent spring contact being effective upon failure of the actuating means including spring means to close the switch to thereby signal the failure.
 3. In a lock assembly having a casing, a core rotatable in the casing and having a central key receiving slot, and locking means acting between the core and the casing to normally lock the core from rotation in the casing and to unlock the core to permit rotation when a properly bitted key is inserted into the key slot, a switch for indicating the preSence of the key in the key slot of the core and comprising: a switch housing of dielectric material mounted on the casing, laterally spaced first and second electrical contacts mounted on the switch housing, an elongated spring contact having one end mounted on the housing and the other end contacting the laterally spaced electrical contacts, the spring contact being bent intermediate its ends to provide a first ridge engaging the housing and a second ridge, an actuating lever pivotally mounted to the housing and engageable with the second ridge of the bent spring contact, a plunger mounted in a recess of the core, spring means biasing the plunger to a position wherein the plunger extends into the key slot and also engages and pivots the actuating lever to pivot the spring contact about its first ridge and out of contact with the laterally spaced electrical contacts, the plunger being moved against the bias of the spring means when a key is inserted into the key slot to permit return of the spring contact by its self-bias to the position wherein the laterally spaced electrical contacts are electrically connected. 